This invention relates to a power driven device. More particularly, this invention relates to a power lawn mower including a riding platform for supporting a standing operator.
Conventional hydraulically driven or hydrostatically controlled machines such as power lawn mowers include a pair of drive wheels, each of which is independently operated by a hydraulic or hydrostatic pump coupled to the mower""s engine. A corresponding motor is provided for each drive wheel, each motor being powered by one of the pumps. Each pump includes a control lever for regulating fluid pressure and direction to its corresponding motor. In such a manner the drive wheels of the power device (e.g. lawn mower) are independently controlled so that each may be rotated at variable speeds in both forward and reverse directions.
Accordingly, each drive wheel of hydrostatically controlled mowers may be driven in either the forward or reverse direction and the mower may therefore be turned through various angles. Hand levers for manipulation by the operator on such mowers are typically provided on handle members for moving the individual pump control levers into desired positions. The above described power lawn mowers are commonly referred to as zero turning radius mowers because if operated in a particular or predetermined manner, the right drive wheel and left drive wheel may be rotated in opposite directions at similar speeds thereby allowing the mower to conduct approximate zero radius turns about a central axis or point located between the drive wheels. This, of course, provides for improved maneuverability in tight environments. Exemplary zero turning radius mowers are disclosed, for example, in U.S. Pat. Nos. 5,077,959; 4,967,543; 4,991,382; and 4,920,733.
Conventional power mowers are generally divided into three separate categories: (i) self-propelled walk-behind mowers; (ii) mowers operated by a seated occupant; and (iii) mowers operated by a standing occupant.
U.S. Pat. Nos. 5,077,959; 4,967,543; 4,991,382 and 4,920,733 disclose typical walk-behind power mowers including hydrostatically or hydraulically controlled rear drive wheels. Unfortunately, the operator of walk-behind mowers such as these is forced to continually walk during mowing operations, thereby leading to fatigue. This is, of course, a disadvantage associated with walk-behind mowers, especially in hilly environments. As a result of operator fatigue, mowers controlled by walking operators are generally less productive over extended periods of time. A further disadvantage of walk-behind mowers is that the operator""s feet are left unprotected and thus exposed to potentially dangerous flying debris.
Turning now to power mowers operated by seated occupants, U.S. Pat. Nos. 3,483,682; 4,487,006; 4,316,356; and 4,998,948 disclose typical such mowers. Unfortunately, seated occupant operated mowers tend to have fairly high centers of gravity (i.e. they are top heavy) due to the position of the operator""s center of gravity which is far from the ground. Such high centers of gravity render mowers operated by seated occupants more likely to tip or roll. Because tipping and rolling is more likely to occur as such mowers operate through turns or on hills, seated operators must be very careful in such environments and work at reduced speed. Operation at reduced speeds clearly leads to reduced productivity of the mower. Additionally, seated operators have a hard time ducking under low hanging tree limbs and the like because of the fixed position of the seat and thus the lower half of the operator""s body. Furthermore, seat assemblies on such mowers necessarily increase the overall cost of the mowers.
U.S. Pat. Nos. 2,354,576; 3,485,314 and 5,004,251 disclose power devices operated by standing occupants supported on trailers or sulkies. The operators of these devices (e.g. power mowers) are supported on sulky devices or trailers removably attached to the mower. Thus, the standing operator supporting trailing platforms of these patents are not actually part of the mower, but rather are mower attachments which must be removed or folded up during mower transport. While the trailing platforms or sulky devices of U.S. Pat. Nos. 2,354,576 and 5,004,251 provide for mower operation by a standing occupant, they greatly extend the overall length of the mower system and are rather bulky in nature. Thus, the sulky or standing occupant platforms of these patents must be disconnected or folded up during transport of the mower. This is burdensome and inconvenient. A further problem with removable trailing platforms such as those disclosed in U.S. Pat. Nos. 5,004,251 and 2,354,576 is that they significantly extend the length of the mower thereby decreasing maneuverability in tight spaces. Additionally, because these sulky or attachment devices are not actually part of the mower, they must often be purchased separately thus increasing the overall cost of the mower system.
U.S. Pat. No. 4,878,339 discloses a power lawn mower including a selectively deployable riding platform for supporting a standing operator or occupant. The mower of U.S. Pat. No. 4,878,339 may be operated either as a walk-behind mower or alternatively as a standing occupant/operator mower depending upon whether or not the standing operator platform is deployed. In other words, because the platform is selectively deployable it is non-fixedly mounted to the mower. Unfortunately, in the walk-behind mode, this mower experiences the above-referenced problems associated with typical walk-behind mowers.
In the standing operator mode (i.e. when the riding platform is deployed), the power mower of U.S. Pat. No. 4,878,339 experiences numerous problems. Firstly, the position of the riding platform lengthens the overall length of the mower and renders it difficult to maneuver in tight areas. Furthermore, while the platform of this patent provides for a fairly low center of gravity, its location well behind the rear drive wheel axis and extension substantially behind the rear drive wheels renders it more likely to bottom out or contact the ground when the mower goes over curbs, bumps, or the like.
If the power mower of U.S. Pat. No. 4,878,339 were operated so as to conduct a substantially zero radius turn, the rear drive wheels would be operated in opposite directions at similar speeds and the central turning point would be located between the rear wheels along the rear drive wheel axis. Because the standing occupant platform of the mower of the ""339 patent is not located at or near this central turning axis (i.e. the platform is located well behind the rear drive wheel axis in the standing operator mode), the operator is adversely affected by centrifugal force created during approximate zero radius turns of the mower. The standing operator is also more affected by centrifugal force created during other mower turns. Due to this centrifugal force, the standing operator or occupant of the mower of the ""339 patent is forced to take turns at slower speeds thus reducing the overall productivity of the mower over extended periods of time.
Another problem with the position of the platform of the U.S. Pat. No. 4,878,339 mower is that its location creates a greater tendency for the mower to xe2x80x9cpop wheeliesxe2x80x9d upon acceleration, especially going up hills, because the mower""s center of gravity is moved rearward when it is operated by a standing occupant. The position of the platform of this patent often necessitates the standing operator leaning forward prior to and during acceleration in order to avoid popping such wheelies and possibly tipping over the mower.
It is apparent from the above, that there exists a need in the art for a power lawn mower operable by a standing occupant including a platform for supporting the standing occupant, the platform being positioned on the mower so as to result in the following advantages: (i) a low mower center of gravity resulting in improved drive wheel traction and less susceptibility to tipping or rolling; (ii) a lessened overall length of the mower so as to render it highly maneuverable in tight spaces and environments; (iii) a reduced tendency of the standing operator platform to bottom out or contact the ground when the mower goes over curbs, bumps, or the like; (iv) a platform positioned in a zero turning radius mower such that the operator is substantially unaffected by centrifugal force created during approximate zero radius turns, thereby allowing the operator/mower to take such turns at higher speeds; (v) a platform positioned in a manner such that the mower is less likely to pop wheelies upon acceleration; etc. Each of the above advantages is accomplished by positioning the standing operator platform of the mower substantially between the rear drive wheels.
It is the purpose of this invention to fulfill the above-described needs in the art, as well as other needs which will become apparent to the skilled artisan from the following detailed description of this invention.
Generally speaking, this invention fulfills the above-described needs in the art by providing a zero turning radius power mower for operation by a standing occupant, comprising:
an engine;
at least one cutting member powered by the engine;
first and second rear drive wheels each independently driveable in both forward and reverse directions so as to allow for substantially zero radius turning of the mower about a turning point when the rear drive wheels are driven in a predetermined manner; and
a riding platform for supporting the standing occupant, the riding platform being located close enough to the turning point or axis so that the standing occupant is substantially unaffected by centrifugal force created during zero radius turning of the mower.
This invention further fulfills the above-described needs in the art by providing a power mower for operation by a standing occupant, comprising:
an engine for driving a cutting member;
first and second rear drive wheels each rotatable about a common axis;
a riding platform mounted on the mower for supporting the standing occupant, the platform being located between the first and second rear drive wheels during operation of the mower so that when the standing occupant stands on the platform the standing occupant is between the first and second rear drive wheels at or near the axis, whereby the platform is less susceptible to impacting the ground when going over bumps and the like.
It is an object of this invention to provide a zero radius turning mower for use by a standing occupant, wherein the occucant""s foot platform extends forward of and underneath a frame (e.g. deck) section of the mower so as to protect the occupant""s feet from injury and conserve valued space.
It is another object of this invention to provide a unique handle bar and control configuration for use with such a mower for the purpose of enabling the standing occupant to more easily operate the mower in forward and reverse without losing his/her balance during the process of doing so.
It is still another object of this invention to provide front and side standing occupant thigh rests so that the standing occupant can rest his/her thighs against same during mower operation. In certain preferred embodiments, the hydraulic fluid tank is housed within a portion of this thigh rest structure and an air cooling passage is designed to flow proximate same in order to help maintain the hydraulic fluid tank or reservoir at acceptable temperature(s).
It is still another object of this invention to provide a pump control lockout system for preventing accidental movement of the mower while the parking brake is engaged. Furthermore, according to certain embodiments, a wheelie bar member(s) is/are mounted to the rear of the mower in order to reduce the possibility of extreme backward tipping of the mower when going up hills and the like.
Another object of this invention is to provide a deadman switch (i.e. or operator presence control switch) that functions to stop cutting blade rotation beneath the mower deck in response to the operator stepping off of the foot platform.
It is still another object of this invention to fulfill the above-described needs in the art by providing a zero turning radius self-propelled power mower for operation by a standing occupant, the self-propelled mower comprising:
an engine;
at least one cutting member powered by said engine;
first and second rear drive wheels each independently drivable in both forward and reverse directions so as to allow for substantially zero radius turning of the mower about a turning axis when said rear drive wheels are driven in a predetermined manner, said turning axis being located between said rear drive wheels, and wherein each of said first and second rear drive wheels is rotatable about corresponding axles;
a first hydrostatically powered means connected to said first drive wheel and a second hydrostatically powered means connected to said second drive wheel, said first and second hydrostatically powered means each being positioned proximate the axle of a corresponding wheel so that said first and second means drive said first and second rear drive wheels, respectively, via their axles, said first and second means for driving said rear wheels being located on opposite sides of said turning axis;
a mower deck for housing said at least one cutting member, at least a substantial portion of said mower deck and cutting member being located substantially forward of said first and second rear drive wheels;
a handle member including a hand grip portion, said hand grip portion located forward of said turning axis so that hands of the standing occupant are normally located forward of said turning axis during zero radius turns of the mower;
a foot platform for supporting the standing occupant, wherein said foot platform is located at a position relative to said hand grip portion and said turning axis so that a substantial portion of the standing occupant""s body may be located substantially on said turning axis during zero radius turns of the mower and thus be substantially unaffected by centrifugal force created during zero radius turns of the mower; and
wherein a substantial portion of said foot platform is located at an elevation below or substantially near an axis of at least one of said rear drive wheels (or within the side profile of at least one of the rear drive wheels) so as to create a low center of gravity of the mower.